I just read a fascinating edge talk by Stanislas Dehaene on consciousness. He’s a neuroscientist studying the “easy” problem of consciousness, meaning he’s studying how conscious awareness arises in the brain, not how we get this subject perception of the world. He does some pretty interesting experiments, using MRI to study people’s brain’s as they consciously and subliminally perceive various stimuli. He comes the conclusion that consciousness is when multiple areas of the brain begin to communicate and synchronize on one concept or stimulus. Then it becomes conscious and you can think about, process it in different areas of the brain, etc. Here’s what he says:

This idea is relatively simple, and it is not far from the one that Daniel Dennett proposed when he said that consciousness is “fame in the brain”. What I propose is that “consciousness is global information in the brain” — information which is shared across different brain areas. I am putting it very strongly, as “consciousness is”, because I literally think that’s all there is. What we mean by being conscious of a certain piece of information is that it has reached a level of processing in the brain where it can be shared.

Because it is sharable, your Broca’s area (or the part of it involved in selecting the words that you are going to speak) is being informed about the identity of what you are seeing, and you become able to name what you are seeing. At the same time, your hippocampus is perhaps informed about what you have just seen, so you can store this representation in memory. Your parietal areas also become informed of what you have seen, so they can orient attention, or decide that this is not something you want to attend to… and so on and so forth. The criterion of information sharing relates to the feeling that we have that, whenever a piece of information is conscious, we can do a very broad array of things with it. It is available.

It’s pretty interesting that the main purpose of consciousness may just be so that different parts of the brain can use the information. Suddenly we’re able to think about, visualize, memorize and talk about some particular thing. We can decide to pay attention to it or not. I thought the “all or nothing” principle was particularly interesting:

Another important feature that I have briefly mentioned already is the all-or-none property. You either make it into the conscious workspace, or you don’t. This is a system that discretizes the inputs. It creates a digital representation out of what is initially just a probability distribution. We have some evidence that, in experiments where we present a stimulus that is just at threshold, subjects end up either seeing it perfectly and completely with all the information available to consciousness — or they end up not having seen anything at all. There doesn’t seem to be any intermediate state, at least in the experiments that we’ve been doing.

Having a system that discretizes may help solve one of the problems that John Von Neumann considered as one of the major problems facing the brain. In his book The computer and the brain, Von Neumann discusses the fact that the brain, just like any other analog machine, is faced with the fact that whenever it does a series of computations, it loses precision very quickly, eventually reaching a totally inaccurate result in the end. Well, maybe consciousness is a system for digitizing information and holding on to it, so that precision isn’t lost in the course of successive computations.

I thought the analogy to the computer here was particularly interesting. In robotics, there are plenty of times where we have an uncertain estimate of what is going on. For example in robot localization, we have some distribution over possible places we might be located. But its really hard to determine what to do based on a range of places we might be. So we typically take a single location, the most likely one, and determine behavior based on this. It’s hard to process a large uncertain analog symbol, so we reduce it to a discrete point that we are. It seems like we’re losing valuable information by doing this, but perhaps this is exactly what consciousness is doing. It has to pick out one interesting thing to process at a time, because it’s too difficult to actively do that with many things at once.

Here’s an interesting question: would you rather live 100 years in the past or 100 years in the future? There are good arguments for both sides. Let me try to make a list of advantages for each below.

The past

• Families are closer together geographically.
• Families spend more time together. No tv or video games to distract them.
• Communities are closer together.
• People aren’t as distracted or dumbed down by technology.
• Life is perhaps more of an adventure? Everything is more difficult, from keeping food safe, to traveling, etc.
• Most work is physical, working the land with your hands.

The future

• People are healthier and live longer (better healthcare).
• It’s easy to travel all around the world (or beyond it?).
• You can stay connected with people from everywhere.
• You can get information quickly and easily.
• We’ll have computer or robots that can perform lots of tasks that people do now.

Personally, I am really curious about the future, what it will be like, what we’ll be like, what technologies we’ll have, what we’ll be able to do, etc. I think the past would be neat as well, as it would be nice to have a tight-knit family and community, and I feel like it could be slightly more adventurous, as just traveling across the country would be a big deal.

This is a crazy thought, but I feel an interesting balance between these things in a few decades would be to live on Mars. It’s still the future and you get all of those things. But I also assume its a very small group, tight-knit, probably without tv and those things, and probably working the land to survive (although probably with machines). That can be another blog post: If you could move to Mars, would you? What if you could never come back?